It is known to provide a solids-storage bin adjacent its lower end with a laterally open slot. A feeder wheel having a plurality of radially extending arms is rotated about a vertical axis adjacent this outlet opening so that the orbits of the arms extend into the bin through the opening. As it rotates such a feeder wheel therefore unloads solids from the bin by entraining them laterally outwardly through the outlet.
As the arms of such a feeder wheel are exposed to considerable abrasion it is necessary to be able to replace them periodically. To this end the wheel has a hub formed with a plurality of radially inwardly flaring seats in which the inner ends of the arms are received. Keys are wedged between these inner ends and the inwardly diverging edges of these seats to hold the arms tightly in place.
Such an arrangement makes it still relatively difficult to change the arms of the feeder wheel. In addition the wedges which must be driven radially outwardly to tighten the respective arms are relatively difficult to place properly and can even loosen during use of the device.
Another disadvantage of the standard type wheel described above is that solids can collect under the hub body, leading to eventual breakdown. This is due to the fact that the hub extends beyond the arms toward the table surface of the bin it is normally juxtaposed with, so that this material can get between the table and the hub.